[7] At the Copa Santa Catarina Internacional in October, Moutet again reached the singles final, losing to João Menezes in straight sets.

[11] In October, he won his second title of the year at the Dunlop Srixon Japan Open Junior Championships, this time partnering Akira Santillan.

In June, he made his junior Grand Slam debut when he lost to Lee Duck-hee of South Korea in the first round of the French Open.

His best results came at the AGL Loy Yang Traralgon Junior International in January, where he reached the third round in singles and quarterfinals in doubles, with Orlando Luz.

He began his season in May at the French Open, moving through two rounds before losing to countryman and eventual champion Geoffrey Blancaneaux in three sets.

[16][17] Moutet then competed in the European Summer Cups, helping France win the title, before finishing his year at the US Open, where he lost in the third round.

Seeded sixth, he moved quickly through the first four rounds, dropping only twelve games en route to the semifinals, where he again met Möller.

Partnering with Ergi Kirkin, he also reached the doubles semifinals, losing to Italian pair Francesco Forti and Mattia Frinzi.

Moutet began his professional career when he was given a wildcard into the qualifying event at the Moselle Open, where he won his first round match against Ukrainian Gleb Alekseenko in two sets.

En route, he toppled three seeded players: fifth-seeded Nicolas Reissig, second-seeded Omar Giacalone, and fourth-seeded Riccardo Sinicropi.

Following the French Open, Moutet played four additional Futures events to finish the year, winning only two main draw matches.

At France F5, Moutet defeated three seeded players en route to the second final of his career, where he lost to Raymond Sarmiento of the United States in straight sets.

En route, Moutet defeated eighth-seeded Filipp Kekercheni in the first round, top-seeded Riccardo Bellotti in the semifinals, and fifth-seeded Nino Serdarusic in the final.

After defeating third seed Norbert Gombos in the first round and fellow wildcard Rémi Boutillier in the second, Moutet faced James McGee in the quarterfinals.

Partnering with Constant Lestienne in the doubles, he advanced to the second round, where the pair was defeated by the eleventh seeds, Jean-Julien Rojer and Horia Tecău.

After defeating sixth seed Lukáš Lacko in the first round and Yann Marti in the second, Moutet's run came to an end in the quarterfinals, where he lost to eventual champion Maximilian Marterer.

He won the first ATP World Tour singles main draw match of his career at that tournament when he defeated Adrián Menéndez Maceiras in the first round.

[44] He won the first Grand Slam singles main draw match of his career when he defeated Ivo Karlović in straight sets in the first round.

Moutet reached his first career ATP Tour singles final (where he lost to Andrey Rublev in straight sets) as a qualifier at the 2020 Qatar ExxonMobil Open, after defeating fourth-seeded Milos Raonic in the second round and top-seeded Stan Wawrinka in the semifinals.

At the 2020 French Open Moutet lost to first time main draw qualifier at this Major, Italian Lorenzo Giustino 6–0, 6–7 (7), 6–7 (3), 6–2, 16–18 in the first round.

[48] At the 2021 Estoril Open in April, Moutet defeated another Canadian, the top seeded wildcard Denis Shapovalov, in the second round, before losing to Albert Ramos Viñolas in the quarterfinals.

[50] At the Adelaide International 1 tournament on 5 January 2022, Moutet was disqualified for swearing at the chair umpire immediately after he had lost the second set of his second-round match against Laslo Đere.

[51] Moutet enjoyed a fine run in his next tournament (the Adelaide International 2), winning two qualifying and three main draw matches to reach the semifinals, where he was defeated by his unseeded countryman Arthur Rinderknech 1–6, 3–6.

In September, he won the ATP Challenger Tour Szczecin Open singles title, defeating Dennis Novak in the final.

[58][59] On November 1, right after his first round match win against Borna Coric at the 2022 Rolex Paris Masters,[60] he was expelled from the Federation of French Tennis (FFT) due to repeated bad behavior.

[66] As a result of break due to a wrist surgery in January 2023, and multiple first round losses, including at the 2023 US Open,[67] Moutet dropped out of the Top 100 in September.

[70] He reached the fourth round at the 2024 French Open for the first time in his career defeating 16th seed Nicolás Jarry,[71] Alexander Shevchenko[72] and Sebastian Ofner all in four sets.

This unconventional approach, combined with his flair for drop shots and volleys, often catches opponents off guard and adds an element of unpredictability to his matches.

[85] He idolised Rafael Nadal growing up,[86] and has appeared in numerous video sessions for TopCourt, a popular tennis tutorial website.

In 2020, Moutet dropped his debut hip-hop album, Écorché, and has released several new songs since then, including a track with fellow player Denis Shapovalov.